Wireless communication devices, such as cellular telephones, are used in major metropolitan areas all around the world. However, conventional communication devices don't travel well. As a user goes from one region of the world to another, it is very likely that the communication device he or she is used to using at home does not work in a foreign country. Most likely this is simply because different frequencies are used in different countries for wireless communication, and a communication device bought and used in one region is not designed to work in another region that uses different frequencies.
Some manufacturers of communication devices have addressed this problem. For example, some cellular telephones are designed to use an interchangeable memory card that, among other things, has a list of frequencies to be used in a particular region. This method is effective, but places a burden on the user to remember to purchase additional memory cards for each region he or she is planning on visiting. Furthermore, these cards are easy to lose. Accordingly, many people perceive the use of memory cards as ungainly, and would prefer another option.
An alternative option to memory cards is to simply store a list of all operating frequencies used world wide in the communication device, and begin scanning the list every time the device is powered up. However, this method is not practical because there can easily be thousands of frequencies, especially in linearly modulated digital communication systems since the channel spacing can be very narrow. The time it would take to register for communication service by having to scan the entire list would be on the order of minutes. This would likely not be acceptable for consumer markets. Thus, there is a need for a way by which to eliminate the need for memory cards by including all possible frequencies in the communication device, but without having an excessively long registration time.